The significance of early post-exercise ST segment normalization

Abstract Background The persistence of ST segment depression in recovery signifies a strongly positive exercise treadmill test (ETT). However, it is unclear if early recovery of ST segments portends a similar prognosis. We sought to determine if persistence of ST depression into recovery correlates with ischemic burden based on myocardial perfusion imaging (MPI). Methods This was a retrospective analysis of 853 consecutive patients referred for exercise MPI at a tertiary academic center over a 24-month period. Patients were stratified into three groups based on the results of the ETT: normal (negative ETT), persistence (positive ETT with > 1 mm ST segment depression at 1 minute in recovery) and early normalization (positive ETT with Results A total of 513 patients had a negative ETT, 235 patients met criteria for early normalization, while 105 patients met criteria for persistence. The persistence group had a significantly greater SSS (8.48 ± 7.77) than both the early normalization (4.34 ± 4.98, p  Conclusion Among patients with an electrically positive ETT, recovery of ST segment depression within 1 minute was associated with a lower SSS than patients with persistence of ST depression beyond 1 minute. Furthermore, early ST segment recovery conferred a similar SSS to patients with a negative ETT. These results suggest that among patients evaluated for chest pain with a positive ETT, early recovery of the ST segment during recovery is associated with a significantly less ischemic burden on subsequent MPI and thus may represent a false positive finding in exercise treadmill testing.